One of the most common boiler issues homeowners face is the dreaded low pressure fault code. When your boiler loses pressure, it can stop working properly – leaving you without heating or hot water.
The good news is that in most cases, low boiler pressure is a simple fix that you can carry out yourself, as long as you follow the correct steps and don’t over-pressurise the system.
What Causes a Boiler to Lose Pressure?
Boiler pressure can drop for a number of reasons, including:
- Small leaks in the heating system
- Bleeding radiators (which releases air and lowers system pressure)
- Normal wear and tear over time
If your boiler pressure keeps dropping regularly, it’s best to have a qualified heating engineer inspect your system to rule out hidden leaks or faults.
How to Re-Pressurise Your Boiler
Step 1: Locate the Pressure Gauge
Check the pressure gauge on your boiler. Depending on the make and model, it may be on the front panel or underneath the boiler casing.
- Ideal pressure should be between 1 and 2 bar.
- If the needle is below 1, your boiler needs re-pressurising.
Step 2: Find the Filling Loop
Most pressurised boilers have an external filling loop – a silver braided hose that connects two pipes.
Step 3: Re-Pressurise the Boiler
- Slowly open the taps or valves on the filling loop.
- You’ll hear water entering the system.
- Watch the gauge carefully until it rises to the recommended level (1–2 bar).
- Close both taps and return them to their original position.
This should remove the fault code and allow your boiler to resume normal operation.
In-Built Filling Loops
Some modern boilers have in-built filling loops, so don’t panic if you can’t see an external one. The method to top up varies by manufacturer, so if you’re unsure, check your boiler manual or contact our team at Rix Gas Services and we’ll be happy to guide you through the process.
When to Call an Engineer
If you’re constantly having to re-pressurise your boiler, or if your pressure drops again shortly after topping up, it could point to a leak or a more serious fault. In that case, it’s best to book a professional inspection.
At Rix Gas Services, our engineers can quickly identify the cause of pressure loss and provide lasting solutions to keep your boiler running safely and efficiently.
Contact us today if your boiler keeps losing pressure or you’re unsure how to fix a low pressure fault code.
